In the prior art, a common wireless gateway such as a wireless router usually adopts wired means such as broadband technology or asymmetric digital subscriber line (ADSL) technology to access an upstream network, and Ethernet or wireless local area network (WLAN) is used to access a downstream network. The wireless router provides functions such as dynamic host configuration protocol (DHCP) service, automatic allocation of an Internet protocol (IP) address of a private network, network address translation (NAT) of an IP address, and network firewall, so as to enable multiple users to access a network.
With the development of wireless communication technology, in areas where 3G networks are advanced, a wireless router based on 3G wireless technology (referred to hereinafter as a 3G wireless router) is used to access a network in a wireless manner. A 3G wireless module is added inside the 3G wireless router through a universal serial bus (USB) interface or a personal computer memory card international association (PCMCIA) interface. Through the 3G wireless module, the 3G wireless router accesses a 3G network in a wireless manner, and accesses an upstream network through a 3G network operator.
In the research process of the conventional 3G wireless router, the inventor finds that the same area may be covered by the 3G networks with different modes, such as wideband code division multiple access (WCDMA), code division multiple access (CDMA), and time division-synchronous code division multiple access (TD-SCDMA). Although the conventional 3G wireless router may realize an upstream wireless access to a network, the 3G wireless module in the 3G wireless router can only support a 3G wireless access with a single mode. For example, a WCDMA wireless router includes a WCDMA wireless module, and thus can only access a WCDMA network, and cannot access a CDMA network or TD-SCDMA network. As can be known, the conventional 3G wireless router can only support the 3G network with the single mode, and therefore multi-mode upstream access cannot be satisfied, and the application range of the 3G wireless router is limited. Different wireless routers are required when 3G networks with different modes need to be accessed, thereby adding upstream access cost.